1. Field of the Invention
The present invention relates to a joint mechanism between a power unit and a working unit of a mowing machine, such as a brush cutter, or a trimmer.
2. Description of the Related Art
Mowing machines of the prior art having large total lengths include those which are divided into a power unit (for example, an engine) and a working unit (in a brush cutter, for example, a rod provided with a cutting blade which is rotatably mounted on the end thereof), which can be freely joined and detached. This is so that the mowing machine can be stored or carried easily. A representative configuration of a joint provided in such a mowing machine which can be freely separated and joined is shown in the longitudinal sectional view of FIG. 6 (Japanese Utility Model Publication No. 6-21296). In FIG. 6, C denotes a power unit comprising an engine and B denotes a working unit with a cutting blade (not shown) mounted on the end thereof via a rod 10.
In this configuration of a joint mechanism a casing 21 for a power output section is formed at a protruding side of an output shaft 11 as a part of an engine cover 26 of the power unit C, and the casing 21 has a support member 21a of cylindrical configuration which extends in the axial direction. A holder 22 of cylindrical configuration wherein a rod 10 is mounted is supported by the support member 21a via a cylindrical damper 23 which prevents vibration of the power unit C from being transmitted to the rod 10. In order to prevent the holder 22 and the damper 23 from unintentionally separating from the support member 21a of the casing, a lid member 24, which has an opening 24a formed at the center thereof to allow the rod 10 and a drive shaft 15 to penetrate therethrough, is attached to the end face of the support member 21a on the side of working unit B in the axial direction, (on left-hand side in FIG. 6) by means of a plurality of screws 25.
The holder 22 has a slit 22a formed in the axial direction and flanges 22e, 22f are formed adjacent the slit 22a on both sides thereof as shown in FIG. 7 (view in line VII--VII of FIG. 6). A bolt 13 which is set in a through hole formed in the flange 22f is screwed into a threaded hole formed in the flange 22e, thereby to hold the rod 10 detachably onto the holder 22. The casing 21 has an opening 21d formed therein to face the flanges 22e, 22f inwardly, so that the bolt 13 can be attached, detached and turned from the opening 21d.
As shown in FIG. 6, the support member 21a of the casing rotatably supports an output shaft 11 which is linked to a clutch drum 14 of the engine via a bearing 12 on the side of the power unit C in the axial direction of the support member 21a, namely on a base end side (on right-hand side of the support member 21a in FIG. 6). The output shaft 11 is made in a hollow shape, while the base end of the drive shaft 15 which is arranged rotatably in the rod 10 is linked to the output shaft 11 by means of a spline or the like in the hollow space to rotate together with the output shaft 11.
In a joint mechanism of such a configuration as described above, however, assembling and disassembling of the joint mechanism requires it to attach or detach the lid member 24 onto or from the casing 21 by handling the plurality of screws 25, thus making the operation tedious.